A Home (Evolved) NodeB (H(e)NB) is a base station with small size and low power, which is deployed in indoor places such as home and office, with a main purpose of providing a higher service rate for a user and reducing the expense needed by a high-rate service and meanwhile making up for coverage shortage of an existing distributed cellular wireless communication system. The H(e)NB has advantages in affordable price, convenience, low-power output, plug-and-play, etc.
In an H(e)NB system, an H(e)NB user is connected to a core network through a Home (e)NodeB Access Network (H(e)NB AN). FIG. 1 shows a structure diagram of an HeNB in a Long Term Evolution (LTE) system; FIG. 2 shows a structure diagram of an Home NodeB (HNB) in a Universal Mobile Telecommunications System (UMTS); as shown in FIG. 1 and FIG. 2, an H(e)NB AN consists of an (H(e)NB and a Home (e)NodeB Gateway (H(e)NB GW), wherein the H(e)NB GW mainly has the functions of: verifying the security of the H(e)NB, processing the registration and the access control of the H(e)NB, taking charge of data exchange between a core network and the H(e)NB. An H(e)NB Management System (H(e)MS) mainly operates, maintains and manages the H(e)NB, configures and controls the H(e)NB according to the requirement of an operator, and mainly realizes the function of configuring and managing the H(e)NB, including: verifying location information and configuring H(e)NB parameters; wherein the configuration mainly refers to parameter configuration at a Core Network (CN) level, parameter configuration on a Radio Access Network (RAN) side, and parameter configuration of Radio Frequency (RF), etc.
With the development of H(e)NB technology, in order to realize group management of users, there brings a concept of Close Subscriber Group (CSG) and a cell is described with an access mode, wherein the access mode of the cell can be divided into a Closed access mode, a Hybrid access mode and an Open access mode. The three modes are used to describe the cells with a CSG attribute. The cell of the Closed access mode is called a CSG cell, and only users having subscribed with the CSG of the cell can access the CSG cell, while users not subscribing with the CSG of the cell can not access the CSG cell; the cell of the Hybrid access mode is called a Hybrid cell, wherein not only the users having subscribed with the CSG of the cell can access the Hybrid cell, but also the users not subscribing with the CSG of the cell can access the Hybrid cell, however, the users having subscribed with the CSG of the cell are prior to the users not subscribing with the CSG of the cell in terms of the use of resources, and the charge is different too; for the cell of the Open mode, any user can access the cell, and such cell has no difference from a normal macro cell in terms of access control.
The H(e)NB can be deployed in public places, such as school, shopping mall, etc. There may be a plurality of H(e)NBs deployed inside the same enterprise. In order to accelerate a handover speed, a direct interface between H(e)NBs needs to be taken into account. For an enterprise-level scene, the introduction of a direct interface concept is reasonable and necessary, because in this way not only a handover speed is accelerated but also the signaling load of a core network is reduced.
In both a UMTS system and an LTE system, a direct interface can be established between access network nodes (for example, Radio Network Controllers (RNCs) or eNodeBs), wherein the direct interface between eNBs is an X2 interface, and the direct interface between RNCs is an lur interface. On the premise of meeting the technology requirement, flows such as load balance, information exchange and mobility between base stations can be accomplished more quickly through a direct interface, besides, the signaling overhead of a core network is reduced.
For densely-deployed base stations such as H(e)NBs, since there may be a large number of H(e)NBs which establish direct interfaces and the H(e)NBs have a characteristic of plug and play, the number of direct interfaces between H(e)NBs may become numerous, and the establishment and maintenance of the direct interfaces may become complex. However, the H(e)NB, serving as User Equipment (UE), generally has a low hardware capability out of consideration for cost reduction, and the establishment and maintenance of too many direct interfaces would affect the performance of the H(e)NB.